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<span id="Implementing-PARALLEL-construct"></span><div class="header">
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<hr>
<span id="Implementing-PARALLEL-construct-1"></span><h3 class="section">13.10 Implementing PARALLEL construct</h3>

<div class="example">
<pre class="example">  #pragma omp parallel
  {
    body;
  }
</pre></div>

<p>becomes
</p>
<div class="example">
<pre class="example">  void subfunction (void *data)
  {
    use data;
    body;
  }

  setup data;
  GOMP_parallel_start (subfunction, &amp;data, num_threads);
  subfunction (&amp;data);
  GOMP_parallel_end ();
</pre></div>

<div class="example">
<pre class="example">  void GOMP_parallel_start (void (*fn)(void *), void *data, unsigned num_threads)
</pre></div>

<p>The <var>FN</var> argument is the subfunction to be run in parallel.
</p>
<p>The <var>DATA</var> argument is a pointer to a structure used to 
communicate data in and out of the subfunction, as discussed
above with respect to FIRSTPRIVATE et al.
</p>
<p>The <var>NUM_THREADS</var> argument is 1 if an IF clause is present
and false, or the value of the NUM_THREADS clause, if
present, or 0.
</p>
<p>The function needs to create the appropriate number of
threads and/or launch them from the dock.  It needs to
create the team structure and assign team ids.
</p>
<div class="example">
<pre class="example">  void GOMP_parallel_end (void)
</pre></div>

<p>Tears down the team and returns us to the previous <code>omp_in_parallel()</code> state.
</p>





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